WO2019017212A1

WO2019017212A1 - Blood purification device

Info

Publication number: WO2019017212A1
Application number: PCT/JP2018/025578
Authority: WO
Inventors: 仁後藤; 将弘豊田; 村上　智也; 邦彦秋田
Original assignee: 日機装株式会社
Priority date: 2017-07-21
Filing date: 2018-07-05
Publication date: 2019-01-24
Also published as: US20200147291A1; JP7108615B2; EP3656415B1; EP3656415A1; CN110603065A; JPWO2019017212A1; US11458238B2; EP3656415A4

Abstract

The present invention provides a blood purification device that is capable of detecting an abnormal blood vessel puncture state of an artery-side puncture needle or a vein-side puncture needle. This blood purification device is provided with: an oscillation means 8 that is capable of applying an alternating current at a prescribed frequency and of switching said alternating current between multiple frequencies; a measurement means 9 that is capable of measuring the impedance for each of the frequencies; a gauging means 10 that is capable of acquiring frequency characteristics of the impedances; a storage means 11 that is capable of storing impedance frequency characteristic in the case when an artery-side puncture needle a and a vein-side puncture needle b are puncturing a patient's blood vessels normally; and a determination means 12 that is capable of determining whether or not the artery-side puncture needle a or the vein-side puncture needle b is puncturing a blood vessel normally in accordance with a variation between the impedance frequency characteristic acquired by the gauging means 10 and the impedance frequency characteristic stored in the storage means 11.

Description

Blood purification device

The present invention relates to a blood purification apparatus capable of purifying the blood of a patient who circulates extracorporeally by an arterial blood circuit and a venous blood circuit.

Generally, in dialysis treatment, introduction or discharge of dialysate between a blood circuit for circulating the patient's blood extracorporeally, a dialyzer connected in the middle of the blood circuit, an ironing type blood pump, and the dialyzer A dialysis treatment apparatus having a dialysis apparatus main body capable of removing water while performing hemodialysis treatment is used. Since the dialysis treatment performed by such a dialysis treatment device is usually performed for about 4 hours every other day, the hemodynamics of the patient being treated will change significantly, and in particular, excess water removal (water removal) It is an important issue to effectively and reliably prevent the reduction of blood pressure by the

On the other hand, in blood purification treatment, the patient punctures the artery-side puncture needle and the vein-side puncture needle, and the patient's blood is collected from the artery-side puncture needle and blood purification treatment is performed while circulating in the blood circuit extracorporeally. The blood needs to be returned to the patient from the venous puncture needle. However, in the process of circulating blood extracorporeally, the puncture needle is unintentionally pulled out of the patient's puncturing part due to, for example, body movement or the like, and in particular when the vein side puncture needle is pulled out, the blood goes outside. There is a risk of leakage. In order to detect such detachment of the puncture needle, conventionally, a blood purification apparatus capable of determining the withdrawal state of the puncture needle by supplying an alternating current to the blood circuit has been proposed (for example, Patent Documents 1 and 2) reference).

JP, 2010-12286, A JP, 2010-155109, A

However, although the prior art described above can determine the withdrawal state when the arterial puncture needle or the venous puncture needle completely comes off the patient's body, the arterial puncture needle or the venous puncture needle There is a problem that it is not possible to detect a state in which the blood vessel is not punctured normally (a puncture state in which the blood vessel is not normal) while being punctured by the patient's body. It is important to judge this and warn medical personnel, since the puncture state which is not normal for such blood vessels is a sign that the puncture needle is completely detached from the patient's body.

The present invention has been made in view of such circumstances, and an object thereof is to provide a blood purification apparatus capable of detecting an abnormal puncture state of a blood vessel of an artery side puncture needle or a vein side puncture needle.

The invention according to claim 1 comprises an arterial blood circuit having an arterial side puncture needle capable of puncturing a patient attached at its tip, and a venous blood circuit having a venous side puncture needle capable of puncturing a patient attached at its tip; A blood purification device connected to the proximal end of the arterial blood circuit and the proximal end of the venous blood circuit and capable of purifying the patient's blood which is extracorporeally circulated by the arterial blood circuit and the venous blood circuit; A voltage is applied between the arterial electrode and the venous electrode provided in the arterial blood circuit, the venous electrode provided in the venous blood circuit, and the arterial electrode. An alternating current of a predetermined frequency can be supplied to the patient's blood through the arterial puncture needle and the venous puncture needle punctured in a blood vessel (such as vascular access), and the alternating current can be switched to a plurality of frequencies. Oscillation The frequency characteristic of the impedance can be obtained based on the stage and the measuring means capable of measuring the impedance for each frequency of the flow path in which the alternating current is flowed by the oscillating means, and the impedance for each frequency measured by the measuring means Measuring means, memory means capable of storing frequency characteristics of impedance when the artery-side puncture needle and the vein-side puncture needle are normally punctured in the patient's blood vessel, and impedance obtained by the measurement means The arterial side puncture needle or the venous side puncture needle is normally punctured into the patient's blood vessel according to a change in the frequency characteristic, comparing the frequency characteristic with the frequency characteristic of the impedance stored in the storage means. It is characterized in that it comprises a judging means capable of judging whether it is present or not.

The invention according to claim 2 is characterized in that, in the blood purification apparatus according to claim 1, the oscillating means is capable of switching the frequency of the alternating current over the low frequency and the high frequency.

The invention according to claim 3 is the blood purification apparatus according to

claim

1 or 2, wherein the memory means is used for blood purification after introducing the patient's blood into the arterial blood circuit and the venous blood circuit. It is characterized in that the frequency characteristic of the impedance acquired by the measuring means can be stored before starting the treatment.

The invention according to claim 4 relates to the blood purification apparatus according to claim 3, wherein application of alternating current switched to a plurality of frequencies by the oscillating means, acquisition of frequency characteristics of impedance by the measuring means, and determination by the judging means The determination is characterized in that the determination is performed continuously or intermittently from the start to the end of the blood purification treatment.

The invention according to claim 5 is the blood purification apparatus according to claim 3, wherein the frequency characteristic of the impedance stored in the storage means can be sequentially stored for each blood purification treatment and stored as frequency characteristic data of the past impedance. Comparison of the storage means, the frequency characteristic data of the past impedance stored by the storage means, and the frequency characteristic of the impedance stored in the storage means in the present blood purification treatment, and monitoring the change of the frequency characteristic And monitoring means that can be used.

The invention according to claim 6 is the blood purification apparatus according to any one of claims 1 to 5, wherein the arterial side puncture needle or the venous side puncture needle is normally punctured in the blood vessel by the determination means. It is characterized in that it comprises notification means for notifying that it has not been determined.

A seventh aspect of the present invention is the blood purification apparatus according to any one of the first to sixth aspects, wherein the determination means includes frequency characteristics of only the resistance component of the impedance acquired by the measurement means, and the memory. Means is used to compare the frequency characteristics of only the resistance component of the impedance stored, and whether or not the artery-side puncture needle or the vein-side puncture needle is normally punctured into the patient's blood vessel according to changes in the frequency characteristics It is characterized in that it can be determined.

The invention according to claim 8 is the blood purification apparatus according to any one of claims 1 to 7, wherein the arterial electrode and the venous electrode constitute the arterial blood circuit and the venous blood circuit. It is characterized in that it comprises an electrode formed in contact with the outer peripheral surface of the flexible tube, and a voltage can be applied without contacting the fluid flowing through the arterial blood circuit and the venous blood circuit. .

According to the invention of claim 1, it is possible to determine whether or not the artery-side puncture needle or the vein-side puncture needle normally punctures the blood vessel of the patient according to the change in the frequency characteristic of the impedance. It is possible to detect an abnormal puncture state of the arterial side puncture needle or the venous side puncture needle to the blood vessel.

According to the invention of claim 2, since the oscillation means is capable of switching the frequency of the alternating current over the low frequency and the high frequency, it is possible to acquire the frequency characteristic of the impedance over a wide frequency range, The abnormal puncture state of the side puncture needle or the vein side puncture needle to the blood vessel can be accurately determined.

According to the invention of claim 3, the memory means is the frequency of the impedance acquired by the measuring means after introducing the patient's blood into the arterial blood circuit and the venous blood circuit and before starting the blood purification treatment. Since the characteristics can be stored, it is possible to reliably detect changes in the frequency characteristics of the impedance during blood purification treatment and to make an accurate determination by the determination means.

According to the invention of claim 4, the application of the alternating current switched to the plurality of frequencies by the oscillation unit, the acquisition of the frequency characteristic of the impedance by the measurement unit, and the determination by the determination unit are from the start to the end of the blood purification treatment. Since the operation is performed continuously or intermittently, it is possible to reliably determine an abnormal puncture state of the blood vessel of the arterial puncture needle or the venous puncture needle during blood purification treatment.

According to the invention of claim 5, the storage means can store the frequency characteristic of the impedance stored in the storage means sequentially for each blood purification treatment and can be stored as the frequency characteristic data of the past impedance, and the storage means Since the frequency characteristic data of the past impedance and the frequency characteristic of the impedance stored in the storage means in the present blood purification treatment are compared, the monitoring means capable of monitoring the change of the frequency characteristic is provided. It is possible to monitor the condition of the vascular access (blood vessel A of the patient shown in Figs. 7 and 8 etc.) and to perform abnormal puncture on the blood vessel of the arterial or venous puncture needle before the start of the current blood purification treatment. The state can be determined.

According to the invention of claim 6, since the notification means is provided for notifying that the judgment means has determined that the arterial puncture needle or the vein puncture needle is not normally punctured into the blood vessel, the arterial puncture It is possible to make it possible for a nearby medical worker or the like to quickly grasp that the needle or the vein-side puncture needle is not in a state of being properly punctured into the blood vessel, and to perform the work for coping quickly.

According to the invention of claim 7, the determination means compares the frequency characteristic of only the resistance component of the impedance acquired by the measurement means with the frequency characteristic of only the resistance component of the impedance stored by the storage means, and the frequency thereof Since it was possible to determine whether the arterial puncture needle or the venous puncture needle normally punctures the patient's blood vessel according to the change in characteristics, it is easy to perform the arterial puncture based only on the resistance component. An abnormal puncture status of the needle or vein puncture needle into the blood vessel can be determined.

According to the invention of claim 8, the artery-side electrode and the vein-side electrode comprise electrodes formed in contact with the outer peripheral surface of the flexible tube constituting the artery-side blood circuit and the vein-side blood circuit, As it is possible to apply a voltage without contacting the fluid flowing through the side blood circuit and the vein side blood circuit, it is necessary to face and attach the electrode to the blood flow path of the artery side blood circuit and the vein side blood circuit. Thus, it is possible to maintain smooth flow by avoiding the formation of asperities for attaching the electrodes to the blood flow path. In addition, since a voltage can be applied without contacting the blood, a metal having low biocompatibility can be used as an electrode.

Overall schematic view showing a blood purification apparatus according to an embodiment of the present invention A schematic view showing a puncture needle (arterial puncture needle and vein puncture needle) in the same blood purification apparatus A schematic view showing an electrode (arterial electrode or vein electrode) in the same blood purification apparatus Graph showing frequency characteristics of impedance stored by storage means in the same blood purification apparatus Graph showing frequency characteristics of impedance obtained by the measuring means in the blood purification apparatus when the puncture needle is not normally punctured into the blood vessel A circuit diagram showing an equivalent circuit corresponding to the frequency characteristic of the impedance shown in FIG. 5 The schematic diagram which shows the state by which the artery side puncture needle and the vein side puncture needle in the blood purification apparatus were normally punctured with respect to the blood vessel. A schematic view showing a state in which an artery-side puncture needle or a vein-side puncture needle (a vein-side puncture needle in this figure) in the same blood purification apparatus is not normally punctured into a blood vessel. The whole schematic diagram which shows the blood purification apparatus which concerns on other embodiment of this invention In the blood purification apparatus according to still another embodiment of the present invention, the frequency characteristic of only the resistance component of the impedance stored in the storage means and the blood purification apparatus when the puncture needle is not normally punctured in the blood vessel Graph showing the frequency characteristics of only the resistance component of the impedance obtained by the measuring means Side view showing another form of electrode (arterial electrode or vein electrode) in the same blood purification apparatus XII-XII sectional view in FIG. 11 The perspective view which shows the electrode (artery side electrode or vein side electrode) of the other form Side view showing still another form of electrode (arterial electrode or vein electrode) in the blood purification apparatus XV-XV sectional view in FIG. 14

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
The blood purification apparatus according to the present embodiment comprises a hemodialysis apparatus for performing hemodialysis treatment and water removal while circulating the patient's blood extracorporeally, and as shown in FIG. The dialyzer 2 as blood purification means connected, the dialysate introduction line L1 and the dialysate discharge line L2 disposed in the apparatus main body B, the arterial electrode D1 and the venous electrode D2, the oscillation means 8, and the measurement It is configured to include means 9, measurement means 10, storage means 11, determination means 12, and notification means 13.

The blood circuit 1 is composed of a flexible tube through which a fluid such as blood can flow, and is configured to include an arterial blood circuit 1a and a venous blood circuit 1b. An artery-side puncture needle a (see FIGS. 1 and 2) can be connected to the tip of the artery (blood removal or blood collection) side blood circuit 1a, and an ironing type blood pump 3 is disposed on the way Ru. On the other hand, a vein-side puncture needle b (see FIGS. 1 and 2) is connected to the tip of the vein (blood return) -side blood circuit 1b, and an air trap chamber 4 for degassing is connected in the middle There is. In the present specification, the side of the puncture needle for blood removal (blood collection) is referred to as the "artery side", and the side of the puncture needle for blood return is referred to as the "vein side". “Venous side” does not mean that the blood vessel to be punctured is defined by either an artery or a vein.

The artery-side puncture needle a and the vein-side puncture needle b according to this embodiment constitute a puncture needle (access means) capable of puncturing the patient, and as shown in FIG. And a cannula (intravascular needle) attached to the Further, the tip portion f is connected to a joint c made of a hard resin or the like through a flexible tube g for forceps, and as shown in FIG. The tube g and the joint c are integrated.

On the other hand, a joint d made of a hard resin or the like is formed at the tip of the arterial blood circuit 1a and the tip of the vein blood circuit 1b, respectively, and as shown in FIG. With the joint c on the side fitted, the fitted state can be locked by screwing with the lock ring R. In addition, by clamping the flexible tube g for forceps with a forceps, the flow path between the artery side puncture needle a or the vein side puncture needle b and the artery side blood circuit 1a or the vein side blood circuit 1b is blocked. It is supposed to get.

When the blood pump 3 is driven in a state where the patient punctures the artery-side puncture needle a and the vein-side puncture needle b, the patient's blood collected from the artery-side puncture needle a passes through the artery-side blood circuit 1a. After the blood purification is performed by the dialyzer 2, the air trap chamber 4 is defoamed, passes through the vein side blood circuit 1b, and returns to the patient's body through the vein side puncture needle b. As a result, the patient's blood can be purified by the dialyzer 2 while circulating in the blood circuit 1 extracorporeally.

The dialyzer 2 has a blood inlet port 2a, a blood outlet port 2b, a dialysate inlet port 2c, and a dialysate outlet port 2d formed in the housing portion, and among these, the arterial blood circuit 1a is formed in the blood inlet port 2a. The proximal end of the blood supply port 2b is connected to the proximal end of the venous blood circuit 1b. The dialysate inlet port 2c and the dialysate outlet port 2d are respectively connected to the dialysate inlet line L1 and the dialysate outlet line L2 extended from the apparatus main body B.

A plurality of hollow fibers are accommodated in the housing of the dialyzer 2, and the inside of the hollow fibers serves as a blood flow path, and dialysis is performed between the outer peripheral surface of the hollow fiber and the inner peripheral surface of the housing. It is supposed to be the flow path of the liquid. In the hollow fiber, a large number of minute holes (pores) penetrating the outer peripheral surface and the inner peripheral surface are formed to form a hollow fiber membrane, and impurities and the like in blood are contained in the dialysate through the membrane. It is configured to be transparent to

In the device body B, as shown in FIG. 1, a double pump 7 formed across the dialysate introduction line L1 and the dialysate discharge line L2, and a bypass line bypassing the double pump 7 in the dialysate discharge line L2. It comprises with the water removal pump 6 connected. Then, one end of the dialysate introduction line L1 is connected to the dialyzer 2 (dialysate introduction port 2c), and the other end is connected to a dialysate supply device (not shown) for preparing a dialysate having a predetermined concentration. Further, one end of the dialysate discharge line L2 is connected to the dialyzer 2 (dialysate outlet port 2d), and the other end is connected to the drainage means (not shown), and supplied from the dialysate supply device. After the dialysate passes through the dialysate introduction line L1 and reaches the dialyzer 2, it is sent to the drainage means through the dialysate outlet line L2.

The water removal pump 6 is for removing water from the patient's blood flowing through the dialyzer 2. That is, when the dewatering pump 6 is driven, the volume of the liquid discharged from the dialysate discharge line L2 is larger than the amount of the dialysate introduced from the dialysate introduction line L1, and Is removed. The water may be removed from the patient's blood by means other than the dual pump 7 (for example, one using a so-called balancing chamber or the like).

The air bubble detection means 5 comprises a sensor capable of detecting air bubbles (air) flowing through a flexible tube constituting the arterial blood circuit 1a. For example, an ultrasonic vibration element comprising a piezoelectric element and an ultrasonic wave reception comprising a piezoelectric element And an element. And while being able to irradiate an ultrasonic wave from an ultrasonic vibration element toward the flexible tube which comprises the artery side blood circuit 1a, the vibration can be received by an ultrasonic receiving element.

The ultrasound receiving element is configured to change the voltage according to the received vibration, and configured to be able to detect that the air bubble has flowed when the detected voltage exceeds a predetermined threshold. There is. That is, since the attenuation rate of ultrasonic waves is higher in air bubbles than in blood and substitution solutions, air bubbles (gas are generated when the detected voltage exceeds a predetermined threshold value by detecting ultrasonic waves transmitted through the liquid. ) Is detected.

In the present embodiment, the arterial electrode D1 and the venous electrode D2 are provided. Among them, the artery-side electrode D1 is an electrode attached to the artery-side blood circuit 1a (a portion between the arrangement position of the blood pump 3 and the artery-side puncture needle a). The vein-side electrode D2 is an electrode attached to the vein-side blood circuit 1b (a portion between the connection position of the air trap chamber 4 and the vein-side puncture needle b).

The artery-side electrode D1 and the vein-side electrode D2 are made of a conductor connected to a flexible tube, as shown in FIG. 3, and are electrically connected to the oscillation means 8 by connection means such as an alligator clip or the like. And a predetermined voltage can be applied to the blood flowing inside. The arterial side electrode D1 and the venous side electrode D2 are not limited to those shown in FIG. 3, but the blood flowing through the arterial blood circuit 1a and the blood flowing through the venous blood circuit 1b As long as voltage can be applied, it may be in another form (including a form not in direct contact with blood).

As an electrode of the form which does not touch blood directly, as shown to FIGS. 11-13, artery side electrode D1 'and vein side electrode D2' are mentioned. The artery-side electrode D1 ′ and the vein-side electrode D2 ′ are made of, for example, a metal pipe (for example, a stainless steel pipe) formed in a cylindrical shape, a pipe made of conductive rubber or conductive plastic, etc. And attached to the outer peripheral surface of the flexible tube constituting the vein-side blood circuit 1b, and applying a voltage without contacting the fluid flowing through the artery-side blood circuit 1a and the vein-side blood circuit 1b It is made possible.

In addition, as shown in FIGS. 14 and 15, as other types of electrodes that do not directly touch blood, there are an arterial electrode (D1a, D1b) and a venous electrode (D2a, D2b). The arterial electrodes (D1a, D1b) and the venous electrodes (D2a, D2b) are, for example, plate-like electrodes, and the outer peripheral surface of the flexible tube constituting the arterial blood circuit 1a and the venous blood circuit 1b is While being attached in a sandwiching manner, a voltage can be applied without contacting the fluid flowing through the arterial blood circuit 1a and the venous blood circuit 1b. In this case, since the electrode can be formed with a simple configuration, it can be easily applied to flexible tubes having different outer diameters.

Thus, the arterial side electrodes (D1 ', D1a, D1b) and the vein side electrodes (D2', D2a, D2b) are the outer peripheral surface of the flexible tube constituting the arterial side blood circuit 1a and the venous side blood circuit 1b. Since the voltage can be applied without contacting the fluid flowing through the arterial blood circuit 1a and the venous blood circuit 1b, the arterial blood circuit 1a and the vein are formed. It is not necessary to make the electrode face the blood flow path of the side blood circuit 1b and attach it, and it is possible to avoid the formation of the unevenness for attaching the electrode to the blood flow path and to maintain the smooth flow . In addition, since a voltage can be applied without contacting the blood, a metal having low biocompatibility can be used as an electrode.

The arterial electrodes (D1 ', D1a, D1b) and the venous electrodes (D2', D2a, D2b) may be fixed to the arterial blood circuit 1a and the venous blood circuit 1b, or It may be removable. If detachable, arterial side electrodes (D1 ', D1a, D1b) and venous side electrodes (D2', D2a, D2b) can be diverted over a plurality of treatments, thereby reducing cost. Can.

The oscillation means 8 applies a voltage between the artery side electrode D1 and the vein side electrode D2, and is applied to the patient's blood through the artery side puncture needle a and the vein side puncture needle b punctured in the patient's blood vessel. It is possible to flow an alternating current at a frequency of 1. and switch the alternating current to a plurality of frequencies. More specifically, the oscillation means 8 is connected to the artery side electrode D1 and the vein side electrode D2 through wires respectively, and covers the low frequency (eg, several tens Hz) and the high frequency (eg, several MHz) Thus, the alternating current can be supplied while switching the frequency of the alternating current.

The measurement unit 9 is connected to a wire that electrically connects the oscillation unit 8 to the arterial electrode D1 and the vein electrode D2, and a flow path through which an alternating current flows by the oscillation unit 8 (the arterial electrode D1 and the vein It is possible to measure the impedance of each frequency of the arterial puncture needle a and the flow passage through the venous puncture needle b) between the electrodes D2. The measuring unit 9 may be connected to another position as long as it can measure the impedance for each frequency of the flow channel in which the alternating current flows by the oscillating unit 8.

The measuring means 10 comprises an arithmetic circuit and the like electrically connected to the measuring means 9, and can obtain the frequency characteristic of the impedance based on the impedance of each frequency measured by the measuring means 9. The frequency characteristic of the impedance acquired by the measuring means 10 is composed of an impedance distribution indicating the relationship between the resistance component of each impedance and the capacitance component of each impedance.

For example, as shown in FIG. 7, when the artery-side puncture needle a and the vein-side puncture needle b are normally punctured to the blood vessel A (such as vascular access), only blood is considered to be a conductor. , And electrodes and blood as elements constituting the impedance. In this case, when the impedance of each frequency of the flow path through which the alternating current flows is measured by the oscillation means 8 and the resistance component of each impedance is taken along the horizontal axis, and the capacitive component of each impedance is taken along the vertical axis, For example, an impedance distribution (ie, frequency characteristics of impedance) as shown in FIG. 4 can be obtained.

On the other hand, as shown in FIG. 8, either or both of the artery side puncture needle a and the vein side puncture needle b (only the vein side puncture needle b in FIG. 8) is against the blood vessel A (vascular access etc.) When the puncture is not normally performed (the puncture to the patient's body is maintained but the puncture to the blood vessel A is not performed normally), biological tissues other than blood (for example, skin H, subcutaneous tissue I shown in the same figure) Alternatively, since it is considered that a conductor (eg, gauze, tape, etc.) for fixing the puncture needle or the like is included in the conductor, the elements constituting the impedance become complicated and complicated.

In this case, when the impedance of each frequency of the flow path through which the alternating current flows is measured by the oscillation means 8 and the resistance component of each impedance is taken along the horizontal axis, and the capacitive component of each impedance is taken along the vertical axis, For example, an impedance distribution as shown in FIG. 5 (ie, frequency characteristics of impedance) can be obtained. An example of the equivalent circuit in the impedance distribution (frequency characteristic of impedance) shown in FIG. 5 is shown in FIG.

The memory means 11 can memorize frequency characteristics of impedance when the artery side puncture needle a and the vein side puncture needle b are normally punctured to the blood vessel A of the patient as shown in FIG. In the present embodiment, after the patient's blood is introduced to the arterial blood circuit 1a and the venous blood circuit 1b (electrically after the blood removal), the blood purification treatment is started. It is configured to be able to store the frequency characteristic of the impedance acquired by the measuring means 10 before the start.

That is, the memory means 11 is an impedance acquired by the measuring means 10 after introducing the patient's blood into the arterial blood circuit 1a and the venous blood circuit 1b (after blood removal) and before starting the blood purification treatment. Is configured to be stored as frequency characteristics of impedance when the arterial side puncture needle a and the venous side puncture needle b are normally punctured to the blood vessel A of the patient.

The determination unit 12 is electrically connected to the measurement unit 10 and the storage unit 11 and compares the frequency characteristic of the impedance acquired by the measurement unit 10 with the frequency characteristic of the impedance stored in the storage unit 11. The arterial side puncture needle a or the venous side puncture needle b (any one or both of the arterial side puncture needle a and the venous side puncture needle b) is normally punctured into the patient's blood vessel according to the change in its frequency characteristics. It can be judged whether or not it is.

That is, before blood purification treatment, as shown in FIG. 7, artery side puncture needle a and vein side puncture needle b are normally punctured to blood vessel A, and during blood purification treatment, as shown in FIG. When one or both of the puncture needle a and the vein-side puncture needle b no longer normally puncture the blood vessel A, the frequency characteristic of the impedance acquired by the measuring means 10 is the initial distribution shown in FIG. Since it changes, for example, becomes the distribution shown in FIG. 5, the artery-side puncture needle a or the vein-side puncture needle b is not normally punctured into the blood vessel by determining that the change has become a certain level or more. It can be determined that

In addition, when the artery-side puncture needle a and the vein-side puncture needle b are normally punctured into the blood vessel A during blood purification treatment, the frequency characteristic of the impedance acquired by the measuring means 10 is the initial value shown in FIG. Since the arterial side puncture needle a and the venous side puncture needle b do not change much from the distribution of the blood vessel A, it can be determined that the blood vessel A is normally punctured. Furthermore, during the blood purification treatment, if the arterial side puncture needle a and the venous side puncture needle b completely detach from the patient's body and are withdrawn, the impedance can not be measured by the measurement means 9, and the measurement means 10 Since the frequency characteristic of the impedance can not be acquired at this point, the withdrawal condition can be determined by the determination means 12 based on that.

Moreover, as a determination method by the determination means 12, the cross correlation of each of the resistance component and capacitance component which comprise the frequency characteristic of an impedance can be utilized, The example is demonstrated below.
The resistance component is R, the capacitance component is C, the frequency at the time of measurement is x, and the resistance component in the frequency characteristic when the puncture state is normal with respect to the blood vessel A is Rref (x) and the puncture state is normal. Assuming that the capacitance component in the frequency characteristic is Cref (x), the resistance component in the frequency characteristic to be compared is Rcur (x), and the capacitance component in the frequency characteristic to be compared is Ccur (x), the following arithmetic expression can be obtained . Here, a and b are the lowest frequency and the highest frequency among the frequencies to be switched.

Thus, as the values of R determined by Equation 1 and C determined by Equation 2 are closer to 0, the frequency characteristics when the puncture state is normal approximate the frequency characteristics of the comparison target (that is, It can be determined that the frequency characteristics do not change much), and it can be determined that the puncturing state to be compared is normal to the blood vessel A. In addition, when either one or both of R obtained by Equation 1 and C obtained by Equation 2 exceeds the predetermined threshold, the frequency characteristics when the puncture state is normal and the frequency characteristics to be compared are similar. It can be determined that there is no (that is, the frequency characteristics have changed), and it can be determined that the puncture state of the comparison object is not normal for the blood vessel A.

In addition, the determination method by the determination means 12 is not limited to the above-mentioned thing, For example, it is good also as other pattern matching etc. which can compare the frequency characteristic in case a puncture state is normal, and the frequency characteristic of comparison object. Further, in the present embodiment, the distribution (graph) showing the frequency characteristic of the impedance is obtained by sequentially plotting the resistance component of each impedance along the horizontal axis and the capacitance component of each impedance along the frequency switching. However, for example, the distribution indicating the frequency characteristics of the impedance may be obtained by sequentially plotting the resistance component of each impedance with the vertical axis and the capacitance component of each impedance as the horizontal axis, and these distributions The pattern matching may be performed and the determination by the determination unit 12 may be performed.

Furthermore, in the present embodiment, the application of alternating current switched to a plurality of frequencies by the oscillation unit 8, the acquisition of the frequency characteristic of the impedance by the measurement unit 10, and the determination by the determination unit 12 end from the start of blood purification treatment. Are configured to be performed continuously or intermittently. Thus, an abnormal puncture state of the blood vessel of the arterial puncture needle a or the venous puncture needle b can be reliably determined during blood purification treatment.

The notifying means 13 notifies that the judging means 12 judges that the arterial side puncture needle a or the vein side puncture needle b is not normally punctured to the blood vessel A, and a predetermined notification (for example, a monitor Etc., and outputting the sound and sound effects, lighting or blinking a warning light, etc.) to the surrounding medical personnel, the arterial side puncture needle a or the vein side puncture needle b against the blood vessel A It is made to understand that it is not punctured normally.

In addition, when the artery-side puncture needle a or the vein-side puncture needle b is not normally punctured into the blood vessel A (although the puncture to the patient's body is maintained, the puncture to the blood vessel A is normal. In addition to the notification of the case where it is not performed, it is configured to notify also when the arterial side puncture needle a or the venous side puncture needle b is completely removed from the patient's body. Thereby, in addition to the case where the arterial side puncture needle a or the venous side puncture needle b is separated from the patient's body, it is possible to notify a sign that the arterial side puncture needle a or the venous side puncture needle b is separated from the patient's body it can.

According to the above embodiment, whether or not the artery-side puncture needle a or the vein-side puncture needle b is normally punctured with respect to the blood vessel A can be determined according to the change in the frequency characteristic of the impedance. It is possible to detect an abnormal puncture state of the side puncture needle a or the vein side puncture needle b with respect to the blood vessel A. In particular, the oscillation means 8 according to the present embodiment can switch the frequency of the alternating current over the low frequency and the high frequency, so that it is possible to acquire the frequency characteristic of the impedance over a wide frequency range. It is possible to accurately determine a non-normal puncture state of the puncture needle a or the vein-side puncture needle b with respect to the blood vessel A.

In addition, the storage unit 11 according to the present embodiment is the impedance acquired by the measurement unit 10 after introducing the patient's blood into the arterial blood circuit 1a and the venous blood circuit 1b and before starting the blood purification treatment. Because the frequency characteristics of the above can be stored, it is possible to reliably detect changes in the frequency characteristics of the impedance during blood purification treatment and make the determination means 12 make an accurate determination.

Furthermore, since the notification means 13 for notifying that the artery side puncture needle a or the vein side puncture needle b is not normally punctured to the blood vessel A by the judgment means 12 is provided, the artery side puncture needle a Alternatively, it is possible to quickly make it possible for a nearby medical worker or the like to quickly grasp that the vein side puncture needle b is not in a state of being properly punctured into the blood vessel A, and to perform the work for coping quickly. .

Next, another embodiment of the present invention will be described.
The blood purification apparatus according to the present embodiment comprises a hemodialysis apparatus for performing hemodialysis treatment and water removal while circulating the patient's blood extracorporeally, as in the above embodiment, and as shown in FIG. , A dialyzer 2 as a blood purification means, a dialysate introduction line L1 and a dialysate discharge line L2 disposed in the apparatus main body B, an artery side electrode D1 and a vein side electrode D2, an oscillation means 8, a measurement means 9 includes a measuring unit 10, a storage unit 11, a determination unit 12, a notification unit 13, a storage unit 14, and a monitoring unit 15. In addition, suppose that the same code | symbol is attached | subjected to the component similar to the said embodiment, and those detailed description is abbreviate | omitted.

The storage unit 14 is electrically connected to the storage unit 11, and can sequentially store the frequency characteristic of the impedance stored in the storage unit 11 for each blood purification treatment and store it as frequency characteristic data of the past impedance. . Specifically, the storage unit 14 according to the present embodiment is after introducing the patient's blood into the arterial blood circuit 1a and the venous blood circuit 1b (after blood removal) and before starting the blood purification treatment. The frequency characteristic of the impedance acquired by the measuring means 10 is sequentially stored for each blood purification treatment, and is stored as frequency characteristic data of the past impedance.

The monitoring means 15 is electrically connected to the storage means 11 and the storage means 14, and the frequency characteristic data of the past impedance stored by the storage means 14 and the impedance stored in the storage means 11 in the present blood purification treatment The frequency characteristics can be compared to monitor changes in the frequency characteristics. As the monitoring method by the monitoring unit 15, the cross correlation between the resistance component and the capacitance component constituting the frequency characteristic of the impedance can be used as in the determination method by the determination unit 12 in the above embodiment (Equation 1 , Equation 2).

According to this embodiment, the storage unit 14 stores the frequency characteristics of the impedance stored in the storage unit 11 sequentially for each blood purification treatment, and can store the frequency characteristics data of the past impedance as the frequency characteristic data of the past. Since the frequency characteristic data of the past impedance is compared with the frequency characteristic of the impedance stored in the memory means 11 in the present blood purification treatment, the monitoring means 15 capable of monitoring the change of the frequency characteristic is provided. The patient's vascular access status (stenosis status etc.) can be monitored, and the blood vessel A (vascular access) of the arterial puncture needle a or the venous puncture needle b before the start of the current blood purification treatment An abnormal puncture status can be determined.

That is, since the frequency characteristic of the impedance stored in the memory means 11 is sequentially stored for each blood purification treatment and stored as frequency characteristic data of the past impedance, the frequency characteristic of the impedance before the start of the blood purification treatment starting from now By monitoring the change as compared to the frequency characteristic of the impedance of the patient, it is possible to detect that the patient's vascular access has become constricted over time, or before the start of blood purification treatment, It is possible to detect that the puncture state of the side puncture needle a or the vein side puncture needle b for the blood vessel A (vascular access) is not normal.

As mentioned above, although this embodiment was described, the present invention is not limited to this, for example, the oscillation means 8 is not limited to what can switch the frequency of alternating current over low frequency and high frequency. It may be switchable to a plurality of frequencies or switchable to a plurality of frequencies in a high frequency region. Further, in the present embodiment, after the patient's blood is introduced to the arterial blood circuit 1a and the venous blood circuit 1b, the frequency characteristic of the impedance acquired by the measuring unit 10 before starting the blood purification treatment is Although it is stored in the storage means 11 and is used as the frequency characteristic of a state in which the blood vessel is punctured normally, the other time point (the initial stage of blood purification treatment or the state in which the puncture needle is punctured normally to the blood vessel) The frequency characteristics obtained at the time of confirmation, etc.) may be stored in the storage unit 11, and may be used as the frequency characteristics of a state in which the blood vessel is punctured normally.

In addition, the determination unit 12 compares the frequency characteristic of only the resistance component of the impedance acquired by the measurement unit 10 with the frequency characteristic of only the resistance component of the impedance stored by the storage unit 11, and changes in the frequency characteristic thereof. Accordingly, it may be possible to determine whether the arterial side puncture needle a or the venous side puncture needle b is normally punctured in the blood vessel of the patient. For example, as shown in FIG. 10, when the artery-side puncture needle a and the vein-side puncture needle b are normally punctured in the blood vessel of the patient, the frequency characteristic of only the resistance component of the impedance is P1 and the memory means 11 is used. Is stored if the frequency characteristic P2 matches the frequency characteristic P1 by acquiring the frequency characteristic of the resistance component as P2 based on the resistance component of the impedance for each frequency measured by the measuring means 9 If it is determined that the state (normal puncturing state) is not met, it can be determined that the needle removal state (unnormal puncturing state) is established.

As described above, the determination unit 12 compares the frequency characteristic of only the resistance component of the impedance acquired by the measurement unit 10 with the frequency characteristic of only the resistance component of the impedance stored by the storage unit 11, and By making it possible to determine whether the arterial side puncture needle a or the venous side puncture needle b is normally punctured in the patient's blood vessel according to the change, the artery side puncture can be easily performed based on only the resistance component. An abnormal puncture state of the blood vessel of the needle a or the vein side puncture needle b can be determined.

Furthermore, in the present embodiment, the oscillation unit 8, the measurement unit 9, the measurement unit 10, the storage unit 11, the determination unit 12 and the like (in other embodiments, the storage unit 14 and the monitoring unit 15) Although arranged, it may be arranged in an apparatus (including a personal computer etc.) separate from the apparatus main body B. Furthermore, the blood purification apparatus to be applied is not limited to the hemodialysis apparatus, but may be an apparatus for performing another blood purification treatment.

The frequency characteristic of the impedance obtained by the measuring means is compared with the frequency characteristic of the impedance stored in the memory means, and the arterial or needle puncture needle is directed to the patient's blood vessel according to the change in the frequency characteristic. As long as it is a blood purification apparatus equipped with a determination means capable of determining whether or not the puncture is normally performed, the present invention can be applied to a device having a different external shape or to which another function is added.

1 blood circuit 1a artery side blood circuit 1b vein side blood circuit 2 dialyzer (blood purification means)
3 blood pump 4 air trap chamber 5 air bubble detection means 6 water removal pump 7 duplex pump 8 oscillation means 9 measurement means 10 measurement means 11 storage means 12 determination means 13 notification means 14 storage means 15 monitoring means D1 artery side electrode D2 vein side electrode a Arterial side puncture needle b Venous side puncture needle B Device body L1 Dialysis fluid introduction line L2 Dialysis fluid discharge line R Lock ring

Claims

An arterial blood circuit with an arterial puncture needle attached to the tip that can be punctured by the patient;
A venous blood circuit with a tip of a venous puncture needle that can be punctured by the patient,
Blood purification means connected to the proximal end of the arterial blood circuit and the proximal end of the venous blood circuit and capable of purifying the blood of a patient who circulates extracorporeally by the arterial blood circuit and the venous blood circuit;
In a blood purification apparatus having
An arterial electrode provided in the arterial blood circuit;
A vein electrode provided in the vein blood circuit;
By applying a voltage between the arterial electrode and the venous electrode, an alternating current of a predetermined frequency is applied to the blood of the patient through the arterial puncture needle and the venous puncture needle punctured in the patient's blood vessel. Oscillation means capable of flowing and switching the alternating current to a plurality of frequencies;
Measuring means capable of measuring the impedance for each frequency of the flow path in which alternating current is flowed by the oscillating means;
Measurement means capable of acquiring frequency characteristics of impedance based on the impedance of each frequency measured by the measurement means;
A storage unit capable of storing frequency characteristics of impedance when the arterial puncture needle and the venous puncture needle are normally punctured in the blood vessel of the patient;
The frequency characteristic of the impedance acquired by the measuring means is compared with the frequency characteristic of the impedance stored in the memory means, and the arterial puncture needle or the venous puncture needle is the patient's in accordance with the change in the frequency characteristics. A judging means capable of judging whether or not the blood vessel is punctured normally;
The blood purification apparatus characterized in that it comprises.
The blood purification apparatus according to claim 1, wherein the oscillating means is capable of switching the frequency of the alternating current over the low frequency and the high frequency.
The storage means may store frequency characteristics of the impedance acquired by the measurement means after introducing the patient's blood into the arterial blood circuit and the venous blood circuit and before starting blood purification treatment. The blood purification apparatus according to claim 1 or 2, wherein
The application of alternating current switched to a plurality of frequencies by the oscillation means, the acquisition of frequency characteristics of impedance by the measurement means, and the determination by the determination means are continuous or intermittent from the start to the end of blood purification treatment The blood purification apparatus according to claim 3, which is carried out.
Storage means which can sequentially store the frequency characteristics of the impedance stored in the storage means for each blood purification treatment and store it as frequency characteristic data of the past impedance;
Monitoring means capable of comparing the frequency characteristic data of the past impedance stored by the storage means with the frequency characteristic of the impedance stored in the storage means in the present blood purification treatment and monitoring changes in the frequency characteristic When,
The blood purification apparatus according to claim 3, comprising:
6. The information processing apparatus according to any one of claims 1 to 5, further comprising notification means for notifying that the judgment means has determined that the arterial puncture needle or the vein puncture needle is not properly punctured in the blood vessel. The blood purification apparatus according to any one of the preceding claims.
The determination means compares the frequency characteristic of only the resistance component of the impedance acquired by the measurement means with the frequency characteristic of only the resistance component of the impedance stored by the storage means, and responds to the change of the frequency characteristic. The blood according to any one of claims 1 to 6, characterized in that it is possible to determine whether or not the artery-side puncture needle or the vein-side puncture needle normally punctures a blood vessel of a patient. Purification device.
The artery-side electrode and the vein-side electrode include electrodes formed in contact with the outer peripheral surface of a flexible tube constituting the artery-side blood circuit and the vein-side blood circuit, and the artery-side blood circuit and the vein-side blood The blood purification apparatus according to any one of claims 1 to 7, wherein a voltage can be applied to the liquid flowing in the circuit without contacting the liquid.